Water soluble cationized polymers such as cationized cellulose and cationized guar gum have been conventionally used for hair cleansing agents in order to provide the hair with conditioning effects. Cationized polymers in hair cleansing agents are thought to provide the hair with conditioning effects by easily remaining on the hair surface as a water insoluble complex formed with an anionic surfactant when they are diluted with water. They are however not so effective for the hair damaged by chemical treatment with a hair coloring agent, permanent wave agent or the like, and a phenomenon of tangling or friction between individual hairs still occurs while the agent is rinsed off.
In order to improve the conditioning effects, proposed is the use of a cationized tara gum obtained by cationizing a polysaccharide available from the endosperm of the seeds of tara (scientific name: Caesal pinia Spinosa) that is a leguminous plant (JP-A-2004-203801). It is also proposed to use a cationized tara gum in combination with cationized guar gum in a hair cleansing agent (JP-A-2005-272658). However, the conditioning effects on the damaged hair are still insufficient.
Amino-modified silicones are sometimes added to hair cleansing agents in order to improve the conditioning effects. A hair cleansing agent containing an amino-modified or ammonium-modified silicone having a high molecular weight is described In JP-A-5-85918. The amino-modified silicone or the like described therein has, in a side chain of the polysiloxane backbone thereof, an alkylene amine or alkylene ammonium salt so that the agent has a high hydrophobic property and as a result, has problems in the stability because of poor solubility or dispersibility in the hair cleansing agent. In addition, it reduces the foaming of the hair cleansing agent and the hair becomes tough or greasy at the time of rinsing off of the agent.